I am making a pattern-welded Viking-age double-edged sword. The blade has previously been forged by welding together pattern welded rods and high carbon edge billets. In this video, I am grinding the fuller and bevels and perform the critical heat treatment step, which involves bringing the blade up to critical temperature, quenching it to create martensite, and then tempering it. The heat treatment process is different from the process depicted in the video game Skyrim, where the character uses a grindstone.